Edoardo Rossi

Last Name

Rossi

First Name

Edoardo

ORCID

0000-0002-2710-5887

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Publications 1 - 10 of 28

The Effects of High Heating Rate and High Temperature on the Rock Strength: Feasibility Study of a Thermally Assisted Drilling Method
Rossi, Edoardo; Kant, Michael; Madonna, Claudio; et al. (2018)
Rock Mechanics and Rock Engineering
In this paper, the feasibility of a thermally assisted drilling method is investigated. The working principle of this method is based on the weakening effect of a flame-jet to enhance the drilling performance of conventional, mechanical drilling. To investigate its effectiveness, we study rock weakening after rapid, localized flame-jet heating of Rorschach sandstone and Central Aare granite. We perform experiments on rock strength after flame treatments in comparison to oven heating, for temperatures up to 650 °C and heating rates from 0.17 to 20 °C/s. The material hardening, commonly observed at moderate temperatures after oven treatments, can be suppressed by flame heating the material at high heating rates. Our study highlights the influence of the heating rate on the mechanism of thermal microcracking. High heating rate, flame treatments appear to mostly induce cracks at the grain boundaries, opposed to slow oven treatments, where also a considerable number of intragranular cracks are found. Herewith, we postulate that at low heating rates, thermal expansion stresses cause the observed thermal cracking. In contrast, at higher heating rates, thermal cracking is dominated by the stress concentrations caused by high thermal gradients.
The effects of flame-heating on the rock strength: Towards a combined thermo-mechanical drilling technology
Rossi, Edoardo; Kant, Michael; Madonna, Claudio; et al. (2018)
Thermal Spallation Drilling, an Alternative Drilling Technology for Deep Heat Mining - Performance Analysis, Cost Assessment and Design Aspects
Kant, Michael; Rossi, Edoardo; Höser, Dragana; et al. (2017)
Proceedings, 42nd Workshop on Geothermal Reservoir Engineering
Reducing the efforts to access deep geo-resources by thermally assisting the drilling process
Rossi, Edoardo; Jamali, Shahin; Saar, Martin O.; et al. (2019)
A theory on thermal spalling of rocks with a focus on thermal spallation drilling
Kant, Michael; Rossi, Edoardo; Madonna, Claudio; et al. (2017)
Journal of Geophysical Research: Solid Earth
The effects of flame-heating on rock strength: Towards a new drilling technology
Rossi, Edoardo; Amann, Florian; Saar, Martin O.; et al. (2017)
51st US Rock Mechanics/Geomechanics Symposium 2017
High-speed nanoindentation mapping: A review of recent advances and applications
Rossi, Edoardo; Wheeler, Jeffrey Martin; Sebastiani, Marco (2023)
Current Opinion in Solid State and Materials Science
High-Speed Nanoindentation Mapping (HSNM) has been recently developed and established as a novel enabling technology for fast and reliable assessment of small-scale mechanical properties of heterogeneous materials over large areas. HSNM allows for one complete indentation cycle per second, including approach, contact detection, load, unload, and movement to the nth indent location, thus enabling high-resolution, spatially resolved hardness (H) and elastic modulus (E) mapping. This article reviews the recent advancements in HSNM and its application to support the design, synthesis, and characterization of advanced materials, potentially impacting the ongoing digital and green transitions. A comprehensive review is given of (a) the main experimental features and critical issues of the protocols in comparison with traditional quasi-static nanoindentation, (b) the advanced data analysis tools employed, and (c) the combination with other microscopy and spectroscopy methods for multi-technique correlative applications. Finally, the relevance of HSNM for selected classes of materials is discussed, including (i) additively manufactured metals, (ii) advanced alloys, (iii) composite materials and cement, highlighting the potential for matrix-reinforcement mechanical characterization and optimization routes, (iv) coatings for industrial components and energy/transportation, discussing damage progression identification at the micro-structural level, and (v) natural materials. Ultimately, future perspectives are presented and discussed.
Impact of Temperature on the Performance of Plasma-Pulse Geo-Drilling (PPGD)
Ezzat, Mohamed; Börner, Jascha; Kammermann, Benedikt; et al. (2024)
Rock Mechanics and Rock Engineering
Advanced Geothermal Systems (AGS) may in principle be able to satisfy the global energy demand using standard continental-crust geothermal temperature gradients of 25–35 ∘C/km. However, conventional mechanical rotary drilling is still too expensive to cost-competitively provide the required borehole depths and lengths for AGS. This highlights the need for a new, cheaper drilling technology, such as Plasma-Pulse Geo-Drilling (PPGD), to improve the economic feasibility of AGS. PPGD is a rather new drilling method and is based on nanoseconds-long, high-voltage pulses to fracture the rock without mechanical abrasion. The absence of mechanical abrasion prolongs the bit lifetime, thereby increasing the penetration rate. Laboratory experiments under ambient-air conditions and comparative analyses (which assume drilling at a depth between 3.5 and 4.5 km) have shown that PPGD may reduce drilling costs by approximately 17–23%, compared to the costs of mechanical drilling, while further research and development are expected to reduce PPGD costs further. However, the performance of the PPGD process under deep wellbore conditions, i.e., at elevated temperatures as well as elevated lithostatic and hydrostatic pressures, has yet to be systematically tested. In this paper, we introduce a standard experiment parameter to examine the impact of deep wellbore conditions on PPGD performance, namely the productivity (the excavated rock volume per pulse) and the specific energy (the amount of energy required to drill a unit volume of rock). We employ these parameters to investigate the effect of temperature on PPGD performance, with temperatures increasing up to 80 ∘C, corresponding to a drilling depth of up to approximately 3 km.
The influence of thermal treatment on rock–bit interaction: a study of a combined thermo–mechanical drilling (CTMD) concept
Rossi, Edoardo; Saar, Martin O.; Rudolf von Rohr, Philipp (2020)
Geothermal Energy
To improve the economics and viability of accessing deep georesources, we propose a combined thermo–mechanical drilling (CTMD) method, employing a heat source to facilitate the mechanical removal of rock, with the aim of increasing drilling performance and thereby reducing the overall costs, especially for deep wells in hard rocks. In this work, we employ a novel experiment setup to investigate the main parameters of interest during the interaction of a cutter with the rock material, and we test untreated and thermally treated sandstone and granite, to understand the underlying rock removal mechanism and the resulting drilling performance improvements achievable with the new approach. We find that the rock removal process can be divided into three main regimes: first, a wear-dominated regime, followed by a compression-based progression of the tool at large penetrations, and a final tool fall-back regime for increasing scratch distances. We calculate the compressive rock strengths from our tests to validate the above regime hypothesis, and they are in good agreement with literature data, explaining the strength reduction after treatment of the material by extensive induced thermal cracking of the rock. We evaluate the new method’s drilling performance and confirm that thermal cracks in the rock can considerably enhance subsequent mechanical rock removal rates and related drilling performance by one order of magnitude in granite, while mainly reducing the wear rates of the cutting tools in sandstone.
Enhancing deep geo-resource utilization by advanced drilling technologies: CTMD and PPGD
Rossi, Edoardo; Adams, Benjamin; Vogler, Daniel; et al. (2020)
Abstract Volume 18th Swiss Geoscience Meeting

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